Quantification of methane and carbon monoxide from natural gas streetlights in Boston: a ‘low-hanging fruit’ for emissions reduction

Natural gas is a primary target for methane (CH _4 ) emissions reductions because this sector is among the largest sources of CH _4 in the United States; natural gas is a fossil fuel, so reducing gas use can also reduce greenhouse gas emissions; and reducing natural gas will improve air quality, safety, and health. Here we present the first study to quantify greenhouse gas emissions and air pollution from natural gas streetlights. We identified and mapped almost 3000 natural gas streetlights in the City of Boston; we also measured CH _4 and carbon monoxide (CO) from 119 gas streetlights in representative neighborhoods. Gas streetlights are emitting both CH _4 (average 1.2 ± 2.1 g CH _4 hr ^−1 ) and CO (average 0.5 ± 0.6 g CO hr ^−1 ), with a skewed distribution of emissions. Natural gas streetlights are emitting more CH _4 than appliances such as stoves and hot water heaters. Boston gaslights are emitting approximately 2% of the gas that supplies them, also higher than other appliances at the end of the gas supply chain. Some streetlights are close enough to windows, doors, or balconies that they could be a direct threat to health of occupants through CO emissions. Gas streetlights emit 1%–2% of Boston’s annual CH _4 emissions, and electrification of gaslights will result in hundreds of thousands of dollars per year in annual savings for the city, in addition to climate, health, and safety co-benefits. Electrifying these prominent symbols may also help further encourage the fossil fuel transition.